Astragalus lentiginosus var. iodanthus, commonly known as Humboldt River milkvetch or violet milkvetch, is a perennial herb native to arid and semi-arid regions in the western United States, including California, Idaho, Nevada, Oregon, and Utah. It is typically found in open habitats such as sagebrush steppe, desert washes, and volcanic fields, where it adapts to barren sandy and volcanic soils. The plant forms a low, spreading mat with prostrate stems that can reach up to 16 inches long. Its compound leaves are made up of 9 to 21 rounded or teardrop-shaped leaflets.

Humboldt River milkvetch blooms from late spring to early summer, producing an inflorescence that is a raceme of flowers in shades of reddish purple or white to cream with purple tips. The flowers are modest in size but can be quite showy when numerous, attracting pollinators. The resulting fruit is a legume pod that becomes dark, mottled, and leathery as it matures. This species is valued for its drought tolerance and ability to thrive in poor soils, making it suitable for xeriscaping and restoration projects. It requires minimal water once established, prefers full sun, and is adapted to soils with fast drainage. While not commonly used in ornamental horticulture, it can be an interesting addition to native plant gardens or naturalized areas. Potential problems include susceptibility to root rot in poorly drained soils and herbivory by animals in its native range.CC BY-SA 4.0